<?php //$Id: lib.php,v 1.1.2.4 2008/10/15 05:29:48 dongsheng Exp $

require_once($CFG->dirroot.'/user/filters/text.php');
require_once($CFG->dirroot.'/user/filters/date.php');
require_once($CFG->dirroot.'/user/filters/select.php');
require_once($CFG->dirroot.'/user/filters/simpleselect.php');
require_once($CFG->dirroot.'/user/filters/courserole.php');
require_once($CFG->dirroot.'/user/filters/globalrole.php');
require_once($CFG->dirroot.'/user/filters/profilefield.php');
require_once($CFG->dirroot.'/user/filters/yesno.php');
require_once($CFG->dirroot.'/user/filters/user_filter_forms.php');


/**
 * User filtering wrapper class.
 */
class user_filtering {
	var $_fields;
	var $_addform;
	var $_activeform;

	/**
	 * Contructor
	 * @param array array of visible user fields
	 * @param string base url used for submission/return, null if the same of current page
	 * @param array extra page parameters
	 */
	function user_filtering($fieldnames=null, $baseurl=null, $extraparams=null) {
		global $SESSION;

		if (!isset($SESSION->user_filtering)) {
			$SESSION->user_filtering = array();
		}

		if (empty($fieldnames)) {
			$fieldnames = array('realname'=>0, 'lastname'=>1, 'firstname'=>1, 'email'=>1, 'city'=>1, 'country'=>1,
								'confirmed'=>1, 'profile'=>1, 'courserole'=>1, 'systemrole'=>1,
								'firstaccess'=>1, 'lastaccess'=>1, 'lastlogin'=>1, 'username'=>1, 'auth'=>1, 'mnethostid'=>1);
		}

		$this->_fields  = array();

		foreach ($fieldnames as $fieldname=>$advanced) {
			if ($field = $this->get_field($fieldname, $advanced)) {
				$this->_fields[$fieldname] = $field;
			}
		}

		// fist the new filter form
		$this->_addform = new user_add_filter_form($baseurl, array('fields'=>$this->_fields, 'extraparams'=>$extraparams));
		if ($adddata = $this->_addform->get_data(false)) {
			foreach($this->_fields as $fname=>$field) {
				$data = $field->check_data($adddata);
				if ($data === false) {
					continue; // nothing new
				}
				if (!array_key_exists($fname, $SESSION->user_filtering)) {
					$SESSION->user_filtering[$fname] = array();
				}
				$SESSION->user_filtering[$fname][] = $data;
			}
			// clear the form
			$_POST = array();
			$this->_addform = new user_add_filter_form($baseurl, array('fields'=>$this->_fields, 'extraparams'=>$extraparams));
		}

		// now the active filters
		$this->_activeform = new user_active_filter_form($baseurl, array('fields'=>$this->_fields, 'extraparams'=>$extraparams));
		if ($adddata = $this->_activeform->get_data(false)) {
			if (!empty($adddata->removeall)) {
				$SESSION->user_filtering = array();

			} else if (!empty($adddata->removeselected) and !empty($adddata->filter)) {
				foreach($adddata->filter as $fname=>$instances) {
					foreach ($instances as $i=>$val) {
						if (empty($val)) {
							continue;
						}
						unset($SESSION->user_filtering[$fname][$i]);
					}
					if (empty($SESSION->user_filtering[$fname])) {
						unset($SESSION->user_filtering[$fname]);
					} 
				}
			}
			// clear+reload the form
			$_POST = array();
			$this->_activeform = new user_active_filter_form($baseurl, array('fields'=>$this->_fields, 'extraparams'=>$extraparams));
		}
		// now the active filters
	}

	/**
	 * Creates known user filter if present
	 * @param string $fieldname
	 * @param boolean $advanced
	 * @return object filter
	 */
	function get_field($fieldname, $advanced) {
		global $USER, $CFG, $SITE;

		switch ($fieldname) {
			case 'username':	return new user_filter_text('username', get_string('username'), $advanced, 'username');
			case 'realname':	return new user_filter_text('realname', get_string('fullname'), $advanced, sql_fullname());
			case 'lastname':	return new user_filter_text('lastname', get_string('lastname'), $advanced, 'lastname');
			case 'firstname':	return new user_filter_text('firstname', get_string('firstname'), $advanced, 'firstname');
			case 'email':	   return new user_filter_text('email', get_string('email'), $advanced, 'email');
			case 'city':		return new user_filter_text('city', get_string('city'), $advanced, 'city');
			case 'country':	 return new user_filter_select('country', get_string('country'), $advanced, 'country', get_list_of_countries(), $USER->country);
			case 'confirmed':   return new user_filter_yesno('confirmed', get_string('confirmed', 'admin'), $advanced, 'confirmed');
			case 'profile':	 return new user_filter_profilefield('profile', get_string('profile'), $advanced);
			case 'courserole':  return new user_filter_courserole('courserole', get_string('courserole', 'filters'), $advanced);
			case 'systemrole':  return new user_filter_globalrole('systemrole', get_string('globalrole', 'role'), $advanced);
			case 'firstaccess': return new user_filter_date('firstaccess', get_string('firstaccess', 'filters'), $advanced, 'firstaccess');
			case 'lastaccess':  return new user_filter_date('lastaccess', get_string('lastaccess'), $advanced, 'lastaccess');
			case 'lastlogin':   return new user_filter_date('lastlogin', get_string('lastlogin'), $advanced, 'lastlogin');
			case 'auth':
				$plugins = get_list_of_plugins('auth');
				$choices = array();
				foreach ($plugins as $auth) {
					$choices[$auth] = get_string("auth_{$auth}title", 'auth');
				}
				return new user_filter_simpleselect('auth', get_string('authentication'), $advanced, 'auth', $choices);

			case 'mnethostid':
				// include all hosts even those deleted or otherwise problematic
				if (!$hosts = get_records('mnet_host', '', '', 'id', 'id, wwwroot, name')) {
					$hosts = array();
				}
				$choices = array();
				foreach ($hosts as $host) {
					if ($host->id == $CFG->mnet_localhost_id) {
						$choices[$host->id] =  format_string($SITE->fullname).' ('.get_string('local').')';
					} else if (empty($host->wwwroot)) {
						// All hosts
						continue;
					} else {
						$choices[$host->id] = $host->name.' ('.$host->wwwroot.')';
					}
				}
				if ($usedhosts = get_fieldset_sql("SELECT DISTINCT mnethostid FROM {$CFG->prefix}user WHERE deleted=0")) {
					foreach ($usedhosts as $hostid) {
						if (empty($hosts[$hostid])) {
							$choices[$hostid] = 'id: '.$hostid.' ('.get_string('error').')';
						}
					} 
				}
				if (count($choices) < 2) {
					return null; // filter not needed
				}
				return new user_filter_simpleselect('mnethostid', 'mnethostid', $advanced, 'mnethostid', $choices);

			default:			return null;
		}
	}

	/**
	 * Returns sql where statement based on active user filters
	 * @param string $extra sql
	 * @return string
	 */
	function get_sql_filter($extra='') {
		global $SESSION;

		$sqls = array();
		if ($extra != '') {
			$sqls[] = $extra;
		}

		if (!empty($SESSION->user_filtering)) {
			foreach ($SESSION->user_filtering as $fname=>$datas) {
				if (!array_key_exists($fname, $this->_fields)) {
					continue; // filter not used
				}
				$field = $this->_fields[$fname];
				foreach($datas as $i=>$data) {
					$sqls[] = $field->get_sql_filter($data);
				}
			}
		}

		if (empty($sqls)) {
			return '';
		} else {
			return implode(' AND ', $sqls);
		}
	}

	/**
	 * Print the add filter form.
	 */
	function display_add() {
		$this->_addform->display();
	}

	/**
	 * Print the active filter form.
	 */
	function display_active() {
		$this->_activeform->display();
	}

}

/**
 * The base user filter class. All abstract classes must be implemented.
 */
class user_filter_type {
	/**
	 * The name of this filter instance.
	 */
	var $_name;

	/**
	 * The label of this filter instance.
	 */
	var $_label;

	/**
	 * Advanced form element flag
	 */
	var $_advanced;

	/**
	 * Constructor
	 * @param string $name the name of the filter instance
	 * @param string $label the label of the filter instance
	 * @param boolean $advanced advanced form element flag
	 */
	function user_filter_type($name, $label, $advanced) {
		$this->_name	 = $name;
		$this->_label	= $label;
		$this->_advanced = $advanced;
	}

	/**
	 * Returns the condition to be used with SQL where
	 * @param array $data filter settings
	 * @return string the filtering condition or null if the filter is disabled
	 */
	function get_sql_filter($data) {
		error('Abstract method get_sql_filter() called - must be implemented');
	}

	/**
	 * Retrieves data from the form data
	 * @param object $formdata data submited with the form
	 * @return mixed array filter data or false when filter not set
	 */
	function check_data($formdata) {
		error('Abstract method check_data() called - must be implemented');
	}

	/**
	 * Adds controls specific to this filter in the form.
	 * @param object $mform a MoodleForm object to setup
	 */
	function setupForm(&$mform) {
		error('Abstract method setupForm() called - must be implemented');
	}

	/**
	 * Returns a human friendly description of the filter used as label.
	 * @param array $data filter settings
	 * @return string active filter label
	 */
	function get_label($data) {
		error('Abstract method get_label() called - must be implemented');
	}
}
